Atomic spectrometry is an analytical technique useful for determining the elemental composition of a sample by its electromagnetic or mass spectrum. Typically atomic spectrometry methods are distinguished by the type of spectrometry used or the atomization source. Types of atomic spectrometry include optical and mass spectrometry. Optical spectrometry can be further divided into absorption, emission and fluorescence spectrometry. Systems for atomic spectrometry include any of a variety of atomization sources. Of atomization sources, flames are the most common due to their low cost and their simplicity. Inductively-coupled plasmas (ICP) are recognized for their outstanding analytical performance and their versatility. To perform atomic spectrometry analysis, the sample is vaporized and atomized. For atomic mass spectrometry, a sample must also be ionized. Vaporization, atomization, and ionization are often, but not always, accomplished with a single source. For efficiency in this process a sample to be analyzed is introduced into the source in droplet form. Pneumatic nebulizers are currently the most widely used sample introduction systems for ICP mass spectrometry.
Pneumatic nebulizers produce droplets of varying sizes and require spray sample chambers to essentially prevent larger droplets from being transported to the atomizer. Thus, a transport efficiency of 20% is expected, with roughly 80% of the sample being wasted. In addition, a peristaltic pump is typically required to deliver liquid to the nebulizer, and use of the pump results in the analytical precision of the measurement being tied to the liquid delivery rate of the pump. Further, the use of the pump tends also to introduce signal perturbations caused by the peristaltic pump pulsations.